Sounds

Recent evenings and early mornings between 2130 and 0100 hours barred owls have called back and forth from our woodlot. One owl has a very distinctive opening hoot. Perhaps it learned to call from a chicken, for a harsh 'cock a doo' like a rooster crow is the nature of its first three syllables with more typical barred owl hoots to finish each call. A barred owl with similar vocabulary called actively in our woodlot during late summer 2005. Then the distinctive call disappeared from our late night listening. However, I heard this same call at one MOMP survey stop in Knox in late March 2006. The Knox location is ~10 km southeast of our woodlot as the owl flies. Was the owl a young bird in 2005 now returned to Thorndike? What is barred owl longevity? Do barred owls return to natal territories when mature? How does an owl know that a territory is vacant? Is one role for calling to determine that a territory is available? Are the 2005, 2006, and 2008 calls identical and by the same bird, or am I delusional? Certainly the owl with the odd call responds to and prompts replies from other barred owls.